This reverts commit a718fcf2.

Change database test settings from "TEST_"-prefixed entries in the
database settings dictionary to setting in a dictionary that is itself
an entry "TEST" in the database settings.

Refs #21775

Thanks Josh Smeaton for review.

Fixed #22073 - Ensure CreateTable operation handles backwards migration correctly when M2M fields are present

Environment keys/values need to use native strings on some
plateforms. Thanks anubhav joshi for detecting the issue and
helping shaping the patch.

Refs #20083.

Refs #21188. Now pure Python DeprecationWarning visibility should
be back to Python defaults.

Thanks Anssi Kääriäinen for the idea and Simon Charette for the
review.

Thanks to jwa for the report.

Also fixed #22124 -- Expanded explanation of exactly what is going on in
as_sql() methods.

Thanks bendavis78 for the report.

This reverts commit 1562b989.

Thanks @apollo13 for the suggestion. Refs #17413.

Thanks Paul McMillan for the review.

Also took the opportunity to slightly refactor gettext options
so as to ease customization by subclassing the command.
Thanks Michal Čihař for the report and initial patch.

Added the following scripts:
* Lithuanian (thanks to petraszd for the patch)
* Serbian (thanks to offy)
* Azerbajani (thanks to Ali Ismayilov)

Fixed the following issues:
* In Polish character map, some uppercase letters were
  converted to a lowercase ascii equivalent.
* The letter Y with a diaeresis had a lowercase version but no uppercase.

The code was also simplified and cleaned up:
* Use of `var` statements everywhere
* Systematic use of semicolons
* Proper looping over arrays and objects.

Thanks to @oinopion for his help in getting the javascript
into proper shape.

Fixes #8561, #11035.

GenericRelation now supports an optional related_query_name argument.
Setting related_query_name adds a relation from the related object back to
the content type for filtering, ordering and other query operations.

Thanks to Loic Bistuer for spotting a couple of important issues in
his review.

Thanks to Loic Bistuer for review. Minor changes to error messages
done by committer.

Refs #21725.

3e25c8ac was an incomplete
merge of the pull request.

Thanks to @ramast for catching this.

Fixed URL resolving in the case where an outer regex includes an inner
regex and both regexes use positional parameters instead of named
groups, causing the outer regex's parameters to override the inner
regex's.

Modified the regex url resolver so that it will concatenates and then
normalizes, instead of normalizing and then concatenating.